13 and 14 Flashcards
What is not an inherited trait?
dogs shaking hands
Where are genes found?
in the DNA in the nucleus
who is the father of evolution
Darwin
who is the father of genetics
Mendel
how many chromosome pairs in humans
23
what happens with cross pollination?
pollination in different plants
what is a genotype
2 alleles
Sexual reproduction
two parents give rise to offspring with unique combinations of genes with fusion of gametes
Asexual reproduction
single individual passes copies of all genes to offspring without fusion of gametes
What are the advantages and disadvantages of sexual reproduction?
Advantages: • “quality over quantity” • genetic variation • spread of advantageous traits • removal of deleterious traits (i.e. eliminate genetic load)
What are the advantages and disadvantages of asexual reproduction?
Advantages:
• Produce very large numbers of offspring
• Don’t have to invest in finding/courting a mate
• Preserve beneficial traits (in a stable environment)
allele
form of a gene
somatic cells
all cells of the body except gametes
gene
form of hereditary units
autosomes
chromosomes that aren’t sex chromosomes
chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
Describe the four hypothesis that Mendel developed based on his experiments with Pea plants.
- Genes are found in alternative versions called alleles
- for each characteristic, an organism inherits an allele from each parent
- dominant allele determines the appearance
- law of segregation
independent assortment
metaphase I
individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together.
crossing over
prophase I
the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.
What does it mean to say that sexual reproduction “purges deleterious traits” from a population?
Independent assortment, random fertilization, shuffling of alleles
Briefly describe the process of meiosis (where does it occur? how many cells result? what kind of cells are produced by meiosis? are they haploid or diploid?)
– Meiosis occurs in the sex organs, producing gametes—sperm and eggs
haploid = gametes fusion= zygote = diploid
what are steps of mitosis
prophase metaphase anaphase telophase cytokinesis
A human cell containing 22 autosomes and a Y chromosome is
sperm
Homologous chromosomes move toward opposite poles of a dividing cell during
meiosis I.
Meiosis II is similar to mitosis in that
sister chromatids separate during anaphase.
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
2x
If we continued to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II would be
x
