Reproduction & Development Flashcards
Asexual Reproduction
One organism divides into two or more offspring
In asexual reproduction, offspring are BLANK to the parent.
genetically identical
The process used to produce identical cells
Mitosis
Clone
Genetically identical to parent organism
Unicellular organisms (single celled) divide by BLANK to produce two identical cells. For example, amoeba and bacteria do this
Mitosis
Mitosis in multi-cellular organisms
Mitosis produces a mass of cells or replaces/ regenerates lost cells that later bud off to form the offspring. Ex hydra, flatworm, starfish
Steps in mitosis
- Chromosomes and genes are copied (DNA replicated)
- Each copy goes into a new cell
- Every cell has the same chromosomes as the original cell
True or false: mitosis leads to variation in the population
FALSE
Problems with no variation in a population
Can’t adapt to changes that happen in the environment. There may be no survivors if the environment contains a factor that the original parent is not adapted to. Ex. no natural selection/evolution of the population
Fitness
Genes with high adaptive value (the genes that allow it to survive) are passed on to the next generation.
Examples of genes with high adaptive value
Resistance genes (antibiotics, pesticides) pass to the offspring
Sexual Reproduction
2 organisms donate 50% of their genes/DNA to form a new individual
Meiosis
Produces sex cells- makes a cell with only half the DNA/ Chromosomes/ genes as the original cell
gametes
Sex cells/sperm/egg. Transfer half of the genetic materials/DNA/chromosomes
Fertilization
Fusion of 2 gametes to form the zygote cell, maintaining the correct chromosome number from one generation to the next. Offspring is a combination of the genes from the parents (not identical to them)
Sexual reproduction increases BLANK
variation
Increasing variation…
Genetic differences in new offspring may inherit fitness/ high adaptive value/ genes that allow it to survive from both parents. Ex) inherits resistance from mom or dad or both, but there’s no guarantee that genes with high adaptive value will be inherited
Human reproduction is regulated by BLANK
Regulated by hormones (estrogen and progesterone for example)
Ovary
Female structure that produces egg (released during ovulation) and secretes hormones (estrogen and progesterone to regulate the cycle)
Oviduct/ Fallopian tube
Female structure, connects ovary area to uterus. This is where fertilization happens
Uterus
Protects fetus (where baby develops/grows)
Placenta
temporary organ that provides nutrients, gas exchange and waste removal for the baby/fetus. Anything (good or bad) that is dissolved in the mother’s blood will diffuse into the baby’s blood through the placenta.
Umbilical cord
Carries baby blood to the placenta then back to the baby
Cervix
Bottom of the uterus which opens into the vagina
Vagina is also called the BLANK
birth canal
Testis
Produces sperm and provides hormone (testosterone) for male traits (beard, voice, muscle mass)
Epididymis
Where sperm mature
Vas deferens
Carry sperm from testis/ epididymis to urethra. This is what is snipped in a vasectomy.
Semen
Mixture of sperm and fluids. Fluid is needed for sperm to swim
Urethra
Passageway leading out of the body for semen and urine
Embryonic Development
One cell turns into two.. etc then 100 billion. Uses mitosis so every cell has identical DNA/Chromosomes/Genes
Differentiation
Cells become different/ specialize depending on what genes are turned on or off (ex nerve cell, skin cell, liver cell)
What influences how genes are turned on or off?
Environmental factors
What happens if the mother is exposed to chemicals or drugs or disease during early pregnancy?
This can affect the embryo in a negative way. Ex alcohol affects brain development.
Embryo
Early stage in the development of humans and other animals or plants.
Progesterone
A type of hormone made by the body that plays a role in the menstrual cycle and pregnancy.
Species
A biological species is a group of organisms that can reproduce with one another in nature and produce fertile offspring.
Estrogen
A type of hormone made by the body that helps develop and maintain female sex characteristics and the growth of long bones.
