Lecture Slides on Reproduction and Genetic Diversity | BIO 1040, Study notes of Biology

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Reproduction

1. Asexual- single parent, genetically identical offspring
2. Sexual- two parents, genetically diverse offspring

Genetic Diversity

1. New gene combination, genotypes
2. May result in new phenotypes
3. May increase survival & reproduction rates

Sexual Plants

1. Alternation of generations
2. General
3. Example

General, Alt of Gen

Pine, Alt of Gen

Asexual Animals

1. Budding- sponges & cnidarians, miniature version of animal grows on adult. When large enough, breaks off

Asexual Animals

3. Fission- corals, flatworms, annelids, new individuals from fission of adult

Asexual Animals

3. Parthenogenesis a. Eggs develop without fertilization b. Male honey bees, haploid c. Some fish & lizards, diploid

Spermatophore

1. Sperm packet
2. Placed on the ground, female picks up, if she finds it, mites & spiders
3. Placed on the female, crayfish
4. Placed in the female, squid

Developmental Stages

1. Zygote- fertilized egg
2. Embryo- cleavage, gastrulation, organogenesis
3. Fetus- adult appearance

Morula

1. Solid ball of undifferentiated, small cells
2. About same size as zygote
3. Cleavage- division of fertilized egg with no increase in size

Blastula

1. Blastocoel- cavity that develops within the cell ball
2. About 7 days in Homo sapiens
3. Blastocyste

Organogenesis

1. Ectoderm, mesoderm, & endoderm rearrange & develop into organs of adult organism
2. Occurs by induction
3. Late embryonic stage, 21 days in Homo sapiens

Induction

1. During gastrulation
2. Fate of embryonic cells determined by chemical messagers produced by gastrula cells
3. Chemical messengers control genetic expression, switch genes of embryonic cells off