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Questions tagged [reproduction]

The biological process by which new individuals are formed.

78 questions with no upvoted or accepted answers
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124 views

Negative association between habitat quality and reproductive success in birds

I'm looking for bird studies that have found either a negative correlation or no correlation between habitat quality and reproductive success. Or in other words, bird studies that have found that ...
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34 views

Can sperm cells penetrate the cell membrane of non-ovum cells?

Sperm cells have tiny bags of enzymes on their tip (the acrosome) which allow them to penetrate the ovum. My question is whether or not the process that allows sperm cells to penetrate the cell ...
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225 views

Are there predefined implantation sites in mammalian uterus?

I do surgical embryo transfer of genetically modified (microinjected) mouse embryos (at 1 or 2 cell stage). As most of the constructs are new, we expect that it may affect birth rate. In case there ...
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407 views

How long does conception take?

I know that conception is a multi-step process. A sperm fuses with an egg. Its contents diffuse into the cytoplasm. Dad's DNA is transported to the nucleus. Proteins are gradually made from Dad's DNA....
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495 views

Mating types in fungi (and somatogamy)

I would have some related questions about the mating types of fungi. Does a single spore generate a mycelium possessing only one mating type? If it does not in general, do Ascomycota and ...
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2k views

Do Asian women have more difficult births than Europeans?

I recently heard a claim that Asians in general have more difficult births than Europeans. Is this true? I have found a few studies(1,2) on the effect of ethnicity on birth outcomes but they seem to ...
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84 views

Division of Polar Body

The first polar body formed after meiosis-I is completed in oocyte, may or may not divide. Why is the statement that "it may or may not divide"? Is it random ?
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50 views

Is mating between human and non-human primates theoretically possible?

I wonder if it is theoretically achievable to produce living offspring between a human and a non-human primate. Great apes have 24 pairs of chromosomes compared to our 23, however, it is known that a ...
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23 views

Looking for realistic representation of angiosperm sperm cells during pollination

I've scoured Youtube, google, and a handful of my botany textbooks for a cellular-scale photo, animation, or video illustrating an angiosperm sperm cell during pollination/fertilization. ...
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148 views

Do ovaries produce estrogen before menarche?

It is traditionally taught that estrogen is produced by the granulosa cells of the follicle. But before menarche, where does the estrogen come from? Is it from the thin layer of granulosa cells lining ...
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348 views

Organisms with one, two, or more than two biological parents

I am interested in the generic names of organisms with one, two, or more than two biological parents. I don't know if the latter possibility is possible in nature, but if it could be, it would ...
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341 views

Is the number of stamens always 9 for geranium?

We are studing in class the reproduction of plants. We start the lesson by observing some components of flowers, it was the Géranium. First of all we start counting the number of sepals , petals and ...
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46 views

Founders of Cnidarian colony

I know that colonial Cnidaria enlarge their colony by the means of asexual reproduction and sexual and asexual reproduction can originate individuals that will be part of other colonies. Nevertheless,...
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1answer
318 views

What is the need for lobules in (human) testicles?

While I was studying the reproductive system, the question popped up in my mind. Each testicle has lobules formed out of the tunica albuginea, in which there exist seminiferous tubules. Why is the ...
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37 views

Volvox Cellular Reintegration

A couple of days ago, I answered this question over on worldbuilding.SE with some information about volvoxes, and commenter Liam Proven pointed out that one of the claims I made was dubious. I had ...
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39 views

What do chimpz/bonobos/orangutangs/gorillas feed their babies with?

I just read this question and it made me curious about what a more original baby diet would look like. So, at what age do our closest relatives in the animal kingdom start giving their offspring more ...
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32 views

Are cloned spieces significantly more vulnereble to deseases than sexually reproducing species?

I would like to be able to compare the risk for species to go extinct implied by their reproduction mechanism in the very short term. Imagine we choose some species A that can reproduce both sexually ...
2
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59 views

Does global sperm count decline also mean lower testosterone?

So I read about the sperm count decline in men in rich countries. I wonder if this is accompanied by other changes for example in testosterone levels or in other hormones linked with the reproductive ...
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30 views

Do marsupials ever die in childbirth?

Question: Do marsupials ever die in childbirth? Obviously the notion of there being a linear ordering of "least advanced" to "most advanced" life forms isn't correct. Still, often marsupials are ...
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37 views

How did genome replication first synchronise with cell division?

It is obvious that cell division in living organisms is now synchronised almost perfectly with DNA replication and, furthermore, the line of division has to intersect exactly the space between the two ...
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36 views

why hens determine the sex of the chick?

So, I have an exercise where I have to correct the second part of the sentence. It goes like this: In hens, the sex of the chicken is determined by hen, because the hen is the heterogametic ...
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585 views

Can telegony happen in humans like in Telostylinus angusticollis?

Is it possible for a human male to transmit features of his phenotype via non-genetic semen-borne factors to his mate's subsequent offspring sired by another male? As it happens in flies (Crean et al.,...
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39 views

Can crocodilians differentiate their offsprings from other young crocodiles?

I read that some species of crocodilians can take care of their young for as long as a year. How do parents differentiate their offsprings from other young crocodiles? Smell, appearance, sound?
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156 views

Why does the ova remain viable for only a day after ovulation?

The ova remains viable for approximately 24 hrs after ovulation to be fertilised by a sperm. ...chances of becoming pregnant increase dramatically if you have sex during the 5 days before ovulation ...
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134 views

Role of neuraminidase in preventing polyspermy in humans

Neuraminidase is a hydrolytic enzyme present in the acrosome of human sperm. It removes neuraminic acid (salic acid) from glycoproteins. I have read in a book that due to this reason it (the enzyme) ...
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156 views

Why is sex pleasure giving activity but not childbirth?

Asking from an evolutionary viewpoint. Sex is a pleasure giving activity so that it encourages reproduction and spreading of genes. But childbirth ,the most crucial part of the reproductive process, ...
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0answers
254 views

What drives male fish to spray their milt?

In mammals the sexdrive of the males is because the intercourse provides a satisfaction where after, the sperm is ejaculated into the female. However, the male sperm doesn't enter the female fish but ...
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39 views

Breeding Southern Right Whales Genetics

I don't know much about biology. I just like watching David Attenborough videos and this made me curious. I just watched this video about breeding Southern Right Whales, and these two quotes puzzled ...
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475 views

Why does it take many sperm for one sperm to fertilize an egg?

Hundreds of acrosomes must undergo exocytosis to digest holes in the zona pellucida. This is one case that does not bear out the adage, “The early bird catches the worm.” A sperm that comes along ...
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255 views

How many mitotic divisions do haploid cells undergo before fertilization?

Background This question is about human physiology and gametogenesis. A spermatozoid is not necessarily the direct "offspring" of a diploid cell. Stated differently, a spermatozoid cell can be the ...
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125 views

Ancestral states of sex determination system

Most (maybe all?) species that reproduce sexually have either genders (anisogamy) or mating types (isogamy). There exist today many different type of sexual determination system. There is a whole ...
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58 views

recombinant gametes

Suppose you are able to observe under a microscope the total number of meiotic divisions occurring in one gonad of a given individual and to outnumber exactly the crossovers between two given loci ...
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161 views

Why does the ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process?

Why does the human ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process??Please help me with it.
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Why are dolphins born tail first?

I heard most dolphins are born tail first. I have read many explanations from books and internet articles and they said that dolphins are born tail first to prevent them from drowning. But now I don'...
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37 views

Mother's physiological response to baby crying

I have read several articles [1,2] that talks about the physiological response in mothers when their babies cry. Is there any studies performed and published that show that this is not true ? https:/...
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21 views

Beyond anabolism, what are factors that restrict growth rate?

Beyond obvious constraints in the case of nutrient limitation, what can explain the relatively slow growth rate of cells in rich media? Lab strains of E. coli grow really, really fast. The cell ...
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0answers
32 views

Fluoroquinolone mitochondrial and genomic DNA adduct

What could be possible consequences of covalent bond mitochondrial and genomic DNA adduct by Fluoroquinolones, our study was done by Fluoroquinolone Toxicity Study NFP. All 50+ participates who took ...
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28 views

Correlation between menstrual period and lunar revolution

Is it just a coincidence that the the length of the entire menstrual cycle from one flow to the other lasts almost exactly as one lunar month?
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139 views

Has Epipremnum aureum lost its ability to reproduce sexually?

In this recent question the shy flowering nature of Epipremnum aureum (Golden Pothos) was discussed: Where can I find a picture of the inflorescence of Epipremnum aureum (golden pothos)? To ...
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0answers
44 views

How diverse are the sperm cells of an individual male due to random mutations?

Due to the sheer number of sperm cells in an individual and the rate of mutations, are they likely to be incredibly diverse and encompass most of what we see across our species? For instance would it ...
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49 views

Homework: Diffrentiate between 2 toads

How to differentiate between 2 toads one of them result of artificial parthenogenesis and the other from renucleation? I answered that the toad resulting from artificial parthenogensis is identical ...
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0answers
100 views

At what level of relation does inbreeding become dangerous?

Inbreeding within first cousins appears to have an established history of dangers, and anything closer than that relationship also. However, how distantly related do two individuals have to be for ...
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108 views

How many ancestral generations do I have?

Following on from this question: How many humans have been in my lineage? Is it almost the same for every human currently living? How many generations back do my ancestors go? Not just human ...
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210 views

What are the absolute facial features which features sexual dimorphism in humans?

Apart from beard and moustache, is there any facial feature that would help to distinguish between men and women? It is said that men have square, rectangular or oblong face and women have oval,...
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39 views

What makes cows stop being able to produce milk?

I'm writing a paper about cows and want to discuss why they stop producing milk. Is there a disease that causes them to stop producing milk?
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34 views

Is it possible to color sperm cells so they look more clear under a microscope?

Im working on something that requires me to check the velocity of a sperm cell under a microscope but I imagine it would be very hard for a program to keep track of the sperm cells.
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22 views

what is the natural way of rose to propagate by its vegetative cells?

I have read that rose reproduces sexually. But I have also heard that it can propagate by its vegetative cells (vegetative cells in its root). Is this correct? If yes, can I know how does it propagate ...
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244 views

Zygote Implantation and Pregnancy Detection

In a normal pregnancy, the embryo (blastocyst) implants between 8-9 days after ovulation. My understanding is that it is able to implant because the fertilized embryo produces a hormone that triggers ...