Questions tagged [sex]

Questions involving the study of sex and reproduction, mating systems, sexuality, sex determination, gender, the evolution of sex, and other topics in the context of sex.

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0answers
119 views

Why can't there be fructification of mycelium in submerged culture?

I am very new at this. I am wondering why fed batch cultures produce a lot of mycelia but no fruit. I thought the more mycelia you had, the greater chance of it forming a fruit body. I am refering to ...
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0answers
113 views

Why did animals evolve genders? [duplicate]

The majority of animals have two genders, and both are needed in reproduction. It seems like it would be more advantageous for creatures to be hermaphrodites, since they could mate with any member of ...
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1answer
1k views

Advantages of bisexual reproduction over asexual one toward species promotion? [duplicate]

Are there any advantages of bisexual reproduction over asexual one towards species conservation and promotion? Do animals that have two or more sexes have more chances to reproduce? Does anybody had a ...
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1answer
687 views

When did our ancestors switch to a menstrual cycle instead of the estrous cycle?

The Wikipedia page on the Estrous cycle says: Humans have menstrual cycles instead of estrous cycles. They shed their endometrium instead of reabsorbing it. Unlike animals with estrous cycles, ...
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3answers
115 views

sex limited genome transmission

In general, for dioecious species, a large portion of the genome passed from parents to offspring of both sexes - in mammals the X-chromosomes and autosomes are passed from a mother to both daughters ...
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1answer
5k views

In males, why it is difficult to control orgasm?

Why it is difficult to control orgasm in male humans? How are orgasms controlled and what is different between males and females? We can control urine for few minutes, but we can't control orgasm for ...
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1answer
549 views

Are there multicellular isogamous species?

Are there multicellular isogamous species? Seeking through the examples of wikipedia I would tend to think that there are no multicellular isogamous species.
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258 views

Why is gynodioecy common and androdioecy rare?

Gynodioecy is when a population features individuals that produce both male and female gametes and individuals that produce just female gametes. Androdioecy is when a population features individuals ...
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0answers
128 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 ...
2
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1answer
2k views

What is the result of meiosis?

Is the result of meiosis ONLY the sex gametes (male and female) which later meet to form a somatic cell? Sometimes I feel as if my book is hinting towards meiosis is the process where sperm cells meet ...
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0answers
381 views

Is there a difference between endorphins that are released while physical activity and sex/masturbation?

I observerd myself and I can identify two different types of "happines". First - called by me - After Pleasure : Occurs AFTER (and last long) long activity that require from me engagement focus and ...
3
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1answer
477 views

Two-fold cost of sex and r/K selection theory

This article cites a bunch of articles (I haven't been through them) that the effect of the two-fold cost of sex is "reduced" in stable environment or in K-selected environment. It says: [..] the ...
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1answer
1k views

Do hormones make men think of sex?

I remember hearing a saying that goes like "men think of sex every 7 minutes (or seconds?)". I take this saying to mean that men have sex related thoughts more often than women. I'm ...
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483 views

Electrodes in the brain and 'repetitive orgasms' [closed]

The advent of chlorpromazine in 1955 put an end to one of the more bizarre chapters in American psychiatry.$^1$ Dr. Robert Heath implanted wires or delivered injections of acetylcholine (a ...
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2answers
636 views

Were early human beings (about 100 - 200 K years ago) far more promiscuous than we are now?

I found that many friends of mine are quite easy in sexual relationship. Ex, I knew a lot of girls went to the night club & met a stranger & brought home to sleep with him even she had never ...
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1answer
401 views

Does recombination increase the additive genetic variance for fitness?

On this article, first column, eighth line of the introduction: By bringing together favourable alleles from different chromosomes, sex and recombination increase the additive genetic variance for ...
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1answer
185 views

Evolution from Mating types to different sexes

Imagine a lineage of multicellular organisms that had mating types and evolved their mating types into sexes. What are the possible mechanisms that might have brought this lineage to evolve sexes from ...
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1answer
157 views

What is the current theory of sexual orientations in Biology?

What is the current explanation of what causes the different sexual orientations in humans.
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1answer
44 views

Could mating/recombination be responsible for evolution of entirely novel features?

The diploid chromosomal architecture is rather interesting. For example, because of diploidy we Humans have to mate. Of course in that sense, because diploid organisms often have mate, this has led to ...
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1answer
954 views

Sexual Differentiation in Monoecious plants with unisexual flowers

In monoecious plants having unisexual flowers (eg Zea Mays, Ricinus Communis etc), there must be some mechanism as to produce two sexually distinct flowers from the same genotype. Since both the type ...
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2answers
717 views

How to know if a woman is fertile without actually making her pregnant?

How to know if a human female is fertile (can give birth to child in future) without making her pregnant? Any signs, tests?
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1answer
301 views

The probability of indirect human fertilization (follow-up)

This question is a follow-up to this one. I've been wondering how small that probability is. As we all know, "safe" sex, that is (correctly) using a condom and all that, isn't perfectly safe. So, in ...
2
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1answer
918 views

How do fully dioecious plants determine sex?

I know that a minority of plants are fully dioecious, with adult plants producing either only male or only female flowers. When is this sexual differentiation determined? Is the seed of such a plant ...
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1answer
483 views

are female bonobos “always” pregnant?

Given that bonobo chimps are more sexually active then humans, are the females almost always pregnant? if not how not? also are they so sexually active in the wild as well or is it just in captivity?
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1answer
637 views

How do members of cryptic species know who to mate with?

According to Wikipedia: In biology, a cryptic species complex is a group of species which satisfy the biological definition of species—that is, they are reproductively isolated from each other—...
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1answer
2k views

How do porcupines keep from pricking each other while mating?

How do porcupines keep from pricking each other while mating? It seems like they would constantly be scratching each other.
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1answer
417 views

How does sex differentiation work in Paracerceis sculpta, the sexually tetramorphic isopod?

Paracerceis sculpta is a marine isopod species known for its unusual reproductive strategy: female: medium-sized; lives in harems run by an α male α male: large; keeps a harem of females β male: ...

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