biological sex and reproduction

Question 1

what are the sex characteristics

Answer 1

• gametes
• gonads (organs that make gametes)
• chromosomes
• genes
• reproductive structures
• secondary sex characteristics ( mammal tissue, body hair, etc.) they are not binary characteristics except for gametes. some of these characteristics are not stable and can vary

Question 2

explain gametes

Answer 2

haploid (n) . when they merge, they will become a diploid (2n).

Question 3

how do we determine the sex of plants or animals

Answer 3

large gametes are eggs
small gametes are male

Question 4

what is isogamy

Answer 4

different types of gamete are the same size. they usually occur in unicellular eukaryotic organisms. the sexes are called mating types (+-) and there can be more than two.

Question 5

what is anisogamy

Answer 5

there is a difference in gamut size

Question 6

what are gonads

Answer 6

produce gametes. testes in sperm making and ovaries in egg making

Question 7

what is hermaphrodite

Answer 7

animals that make eggs and sperm.

Question 8

what are ovotestis

Answer 8

Gonad that produce eggs and sperm. some they can fertilise themselves.

Question 9

what is sequential hermaphrodites

Answer 9

produces egg and sperm in its lifetime but not at the same time

Question 10

explain reproductive structures

Answer 10

assist with helping gamete meet each other.
internal (gametes meet inside the body and external fertilisation (gametes meet in the environment)

Question 11

what does internal fertilisation also assist with

Answer 11

developing and birthing live young (viviparity).
producing and depositing eggs (oviparity).
ovipositor: long structure on female allow them to bury their eggs and develop in safety.

Question 12

explain chromosomes and sex determination

Answer 12

enviromental signals, chromosomes.

Question 13

what are the sex determinate system

Answer 13

-X and Y chromosomes. x is larger than y.
-heterogametic sex (different)
-homogametic sex (both have x)
-ZW sex determination where XY is actually female and xx is male.
XO sex determination: absence of other chromosome determine the sex 1 is male and 2 is female.
haploid and diploid system: two copies of every chromosome is female and one set of chromosomes is male.
- temperature dependant: depending on the weather, offspring will be female or male.
- socially determined sex: role needs to be replaced. eg, in clownfish, if a female dies, one male will turn into female.

Question 14

neoteny

Answer 14

reach sexual development without ‘adult development’. we can induce adult development.

Question 15

explain benefits of aseuxal reproduction.

Answer 15

offspring are not always a perfect clone.
don’t need a mate
invest In ant energy in mating displays 100% of your genes is transmitted. its favourable when environmental conditions are good and they can reproduce rapidly

Question 15

types of aseuxal reproduction

Answer 15

budding: new organism splits off existing one
multicellular asexual reproduction ; CUTTING, pathogenesis (reproduction from an unfertilised egg cell), self fertilisation, afusion, thelytoky: clone offspring from a female. arrhenotoky: not clone because stye can produce male and female. terminal fusion: two eggs fusing. one is heterozygote maybe.

Question 16

benefit of sexual reproduction

Answer 16

more diverse genome, environments are predictable, shaking off parasites (red queen hypothesis).

Question 17

what is isogsametic and anisogamtic

Answer 17

isogametic: same size gametes
anisogamtic: small gametes fuse with larger gametes. females can be more selective because there is more resources needed for their limited amount of gametes while males have low recourse needed. males can sometimes be selective too0 they die after they mate.