bio test 3 animal reproduction and development

Animal reproduction in animals

budding-smaller individual grows off parents

fission-parents split into 2 equal halves

fragmentation and regeneration-small portion breaks off and regrows missing parts

animal reproduction advantages

produce offspring rapidly, reproduce without finding a mate, individuals genetically suited to environment and produce offspring that are identical to parents

animal reproduction disadvantages

no genetic variation, if environment changes individuals may be less suited to new environment

sexual reproduction in animals

created offspring by fertilization, 2 1n gametes fuse to form 2n zygote, requires meiosis

sexual reproduction advantages

genetically diverse offpsring, if environment changes, chance that some individuals well suited to new conditions

sexual reproduction disadvantages

genetically diverse offspring, risk of disease transmission, must find another individual (usually)

reproductive tactics monoecious

both male and female gonads in some individual, may outcross with another individual, fertilize own eggs, advantageous to solitary or less mobile

reproductive tactics dioecious

male and female gonads in different individuals

reproductive tactics external fertilization

gametes released to environment

reproductive tactics internal fertilization

sperm deposited in females

gametogenesis

requires meiosis, only occurs in specialized cells in gonads

spermatogenesis

-testes filled with coiled semiinferous tubules,

-walls of tubules have 2n spermatogonia

-primary spermatocytes are germ cells, mitosis

-secondary finish meiosis ll

-2 spermatids from each secondary

-spermatids mature and differntiate into spermatozoa

oogeneis

ovaries strcuture-2n oogonia

-contained in packet follicle

-oogonia mitosis forms 2n primary oocytes packed in follicles

-primary oocytes-meiosis 1 to produce secondary and polar body

-secondary gets majority of cytoplasm

-polar body disintegrates or

oogenesis graafian follicle

secondary oocyte contained in a large mature graafian follicle, secondary oocyte released during ovultion, if a sperm enters, finishes meiosis ll to produce 1n ovum egg and another polar body

fertilization

1 nuclei of sperm and ovum fuse, forms 2n zygote, zygote to mitosis to embryo, empty follicle becomes a corpus luteum producing hormones to support embryo, disintegrates if no fertilization

Relate the structure of sperm to its role in fertilization.

Head: Holds DNA and enzymes to penetrate the egg.

Midpiece: Has mitochondria for energy.

Tail: Moves the sperm toward the egg.

Summary: Sperm's structure helps it swim, reach, and fertilize the egg.

Compare the types, advantages, and disadvantages of asexual and sexual reproduction.

Asexual reproduction uses one parent, is fast, and produces identical offspring but lacks genetic variation. Sexual reproduction uses two parents, creates variation to adapt, but is slower and produces fewer offspring.

Compare the different reproductive tactics for sexual reproduction

Internal fertilization: inside the female, safer, fewer offspring.

External fertilization: outside the body, many offspring, less protected.

Describe and compare the processes and products of spermatogenesis and oogenesis.

Spermatogenesis: testes, 4 sperm from each cell, happens continuously,

Oogenesis: Occurs in ovaries, produces 1 egg and 3 polar bodies from each cell, releases eggs monthly.

Comparison: Both make gametes by meiosis, spermatogenesis makes many small sperm continuously, while oogenesis makes few large eggs with more nutrients.