Cell Bio Terms Final Exam Flashcards
What does sexual reproduction do that doesn’t happen in asexual reproduction ?
Introduces a variation in the combinations of traits among offspring
What does asexual reproduction produce
Genetically identical copies of a parent
What are genes
Regions in an organisms DNA that encode information about heritable traits
What are alleles?
Different forms of the same gene
What is meiosis
A cytoplasmic division (sexual reproduction)
What does meiosis result in
4 haploid cells
What is a zygote
First cell of a new individual
What happens in meiosis 1
Homologous chromosomes separate
What happens in meiosis 2
Sister chromatid separate
What is the key stage of meiosis 1 and what happens in it
Prophase 1. Synapsis (homologous chromosomes) to form tetrads and pairing at chiasmata. Crossing over.
What is the name of the process of sperm creation
Spermatogenesis
What is the name of the process of egg creation (females)
Oogenesis
What is the result of Spermatogenesis
4 haploid spermatids are formed
What is the result of oogenesis
1 haploid ovum and 3 haploid polar bodies
Describe how sperm are formed
Diploid male sex cell ➡️ (meiosis 1 and cytoplasmic division) primary spermatocyte [diploid] ➡️ (meiosis 2) secondary spermatocytes [haploid] ➡️(cytoplasmic division) spermatids [haploid] ➡️ 4 sperm
Describe how ovum are formed
Oogonium (female sex cell) [diploid] ➡️ (meiosis and cytoplasmic division) primary oocyte [diploid] ➡️ (meiosis 2) first polar body [haploid] and secondary oocyte [haploid] ➡️ three polar bodies [haploid] and one ovum [haploid]
What is fertilization
The fusion of two haploid gametes to result in a diploid zygote
Where does mitosis occur
Somatic cells
Where does meiosis occur
Germ line cells
Meiosis takes a cell that’s ________ and makes it _________
Diploid, haploid
What is a spermatozoan
A mature sperm.
Describe a spermatozoan
Head with DNA and enzyme cap. Mid piece with mitochondria. Flagellum for movement.
Who did the pea plant experiment
Gregor Mendel
Describe why the garden pea was a good model for genetics studies
True breeding
Both self and cross fertilization possible
Short generation time
Easy to work with
What is a mutation
A permanent change in a gene
What is a true breeding lineage
Offspring inherit identical alleles for a trait
What is a hybrid
Has non identical alleles for a trait
What does heterozygous mean
Non indentical alleles of a gene
What does homozygous mean
Identical alleles of a gene
What does a dominant allele do ?
Masks the effect of a recessive allele paired with it
Capital letters signify what
Homozygous dominant
Lower case letters signify what
Homozygous recessive