Sex and gender differences 1 Flashcards
Define sex
Specific a____ that characterise m____ or f____
Includes c____ and other g____ attributes, as well as p____, p____ and b____ differences
Specific attributes that characterise maleness or femaleness. They can include chromosomal and other genetic attributes, as well as physiological, physical and behavioural differences.
Define gender
A person’s internal sense of their gender (experienced gender) or the way in which their gender is perceived by others (expressed gender).
What are Tinbergen (1963) “Four questions”?
- How did the behaviour evolve?
- How does it enhance biological fitness?
- How does it develop in an individual or social group?
- What are the physiological and brain mechanisms involved?
Define haploid and diploid
Haploid - having a single copy of each chromosome in a cell
Diploid - having two copies of each chromosome in a cell
Finish the sentences about sexual reproduction…
1. More complex type of cell division followed by …………
2. Deleterious mutations may accumulate, masked by ……….
3. Risks of finding/competing for ……
- fertilisation
- a normal second copy of a gene
- mates
Compare mitosis and meiosis
In mitosis in a diploid cell (left) the chromosomes replicate and then separate into the daughter cells. In meiosis (right) chromosome duplication is followed by recombination and generation of haploid gametes – Fusion of two gametes in sexual reproduction restores the diploid state.
Fill in the gaps about an evolutionary perspective on sex:
1. Sun and planets condensed out of a spinning gaseous cloud about _____ years ago
2. Earth and a large ______ collided about ____ years ago, resulting in the formation of the ___ and possibly also the large _____ content on Earth
3. Life also evolved some ____ years ago
4. Sexual reproduction evolved in ________ at least _____ years ago
4. Sexual reproduction remains ______, even in those groups where ___________ is also present (e.g. ants, bees, wasps, water fleas)
- 5 billion
- asteroid, 4.5 billion, moon, water
- 4.5 billion
- predominant, parthenogenesis
What are four hypotheses of why sexual reproduction has persisted?
- Recombination of different genotypes during meiosis allows favourable mutations to come together in the same individual.
- Recombination allows more rapid adaptation to fluctuating environments (e.g. to new parasites - the Red Queen hypothesis).
- May help to avoid accumulation of deleterious mutations, especially in stressful environments.
- Parthenogenesis (as in bees, ants & wasps and many other invertebrates) permits rapid exploitation of a favourable environment. Switch back to sex as things become more stressful, favourable season ends etc. Very rare in vertebrates.
The magnitude of a difference between two groups can be expressed as what?
The effect size
(Cohen’s d – the difference in the means divided by the relevant standard deviation)
Sexual dimorphism tends to be high and low in what conditions?
High in primates with significant male-male competition
Low in those that either breed cooperatively or are relatively solitary
Meiosis leads to _______ of gene variants between homologous chromosomes
Recombination
XX mouse embryos with male phenotype can be shown to have incorporated what gene into one of their X chromosomes?
Sry
The human SRY gene can produce what when incorporated into a developing mouse foetus?
masculinisation
In some rare instances, individuals with an XY genotype and female phenotype. These may be accounted for by mutations in the what?
sex steroid signalling pathways
What are hormones?
C____ messangers produced in one part of the b____, typically then r____ into the b____ and act at r____ on cells of another o____ or t____
Chemical messengers produced in one part of the body, typically then released into the blood and act at receptors on cells of another organ or tissue.