ANT Flashcards
(87 cards)
Definition of life history
history of the changes through which an organism passes in its development from birth to death.
Know the different stages of humans’ life history
Pre-natal life
birth
infancy
childhood
juvenile
puberty
adolescence
adulthood: reproductive stage
adulthood: senescence
Know that fitness is a function of survival and fertility
Know the definition of fitness
The ability of an organism to survive and reproduce in its environment, and to pass its genes on to the next generation
Know what happens to our cells during our life cycle (alternating haploid and diploid stages). Know how this relates to the number of chromosomes and pairs of chromosomes in each cell
diploid nucleus of sperm and ovum-producing cells go into meiosis where they become haploid nuclei, fertilization hits and results in a cell called the diploid nucleus of zygote, zygote has 23 pairs of chromosomes, half from maternal and half from paternal, the embryo and then the fetus, infant, will have 46 chromosomes
Know the definition of meiosis and mitosis, and be able to describe both types of cell division
Meiosis is the process leading one diploid cell to turn into 4 haploid cells
Mitosis is the division of a diploid (or haploid) cell that forms 2 identical cells that are also diploid (or haploid)
Know what cells are diploid and what cells are haploid in the human body
Gametes (sperm and egg) are haploid
The rest of our cells are diploids, in short somatic cells
Know in which organs spermatogenesis and oogenesis occur
Spermatogenesis occurs in the testes in the seminiferous tubules
Oogenesis occurs in the ovary
Know when female gametes are formed and what happens to all but 400 of them
Gametes are formed for females during oogenesis when in embryo development. All but 400 of them go under astresia during and after puberty
Define of spermatogonia
an undifferentiated male germ cell
Define oogonia
An immature female germ cell forming oocytes by repeated divisions
define primary spermatocyte
A diploid cell that contains two sets of chromosomes, one from the mother and one from the father, and is a developing male germ cell
Define secondary spermatocyte
a round cell that is produced when a primary spermatocyte divides during the first meiotic division
define spermatid
an immature male sex cell formed from a spermatocyte that can develop into a spermatozoon without further division
Define primary oocyte
an immature female gamete that has started the first stage of maturation, but has not yet completed it (a diploid cell that is arrested in the prophase stage of meiosis)
Define secondary oocyte
A cell that develops after a primary oocyte undergoes the first meiotic division, and is a precursor to the egg
define ovum (ova)
another name for an egg cell
define zygote
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum
Know what happens to parental chromosomes during fertilization
They combine to form a new cell called the zygote
How many chromosomes are there in humans? How many pairs of chromosomes?
46 chromosomes and there are 23 pairs
Define DNA
Carrier of genetic information, it codes for complex molecules called proteins, it determines the phenotype of somebody.
Define histones
Basic proteins found in the nucleus of eukaryotic cells that bind to DNA, allowing it to be condensed to form the structure of chromosomes
Define nucleotides
a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA
How many pairs of nucleotides are there in the human genome
3 billion pairs