Science Flashcards
During what phase do spindle fibers form
Prophase
What is the final phase of mitosis?
Telophase
Mitosis results in the form of what?
Two identical daughter cells
What is the longest phase of the cell cycle?
Interphase
What is the main difference between animal and plant cells
Animal cells have a cell membrane, plant cells have a cell wall
During what phase do chromosomes first become visible
Prophase
What is the purpose of mitosis?
To create two identical daughter cells and replace worn out or lost cells
What is the result of meiosis
Four different daughter cells
Meiosis has how many stages?
2
What is the purpose of meiosis?
To create gamete cells for sexual reproduction
What phase do chromosomes cross over?
Prophase
What is the final phase of meiosis?
Telophase stage 2
Describe two examples of technologies that humans use to select traits of organisms.
- Selective breeding: A way to select and breed living organisms to produce offspring with more desirable traits
- Genetic engineering: a process that changes the DNA of an organism directly.
Who were the earliest “Plant technologists” in North America?
The indigenous people
What crop did the indigenous people develop and how?
Corn from teosinte, they did it by using selective breeding
What are some advantages in biotechnology?
Resistance to disease, better taste or appearance, health improvements
What are some disadvantages to biotechnology?
Weeds will become resistant to herbicide, reduction in genetic variation, genetic defects
What is a fertilized egg called?
A zygote
What are gametes?
Specialized sex cells
What are male gametes?
Sperm cells
What are female gametes?
Egg cells
What does the fertilized egg implant itself in? Why?
The uterus lining, because of the warmth, moisture, and nutrition
What must the male reproductive system do?
To maintain, produce, and transport sperm cells
What must the female reproductive system do?
Create hormones and make it possible to get pregnant.
During ovulation, how many eggs are generally released?
One
How many sperm can fertilize an egg?
One
What happens to the endometrial lining if the egg is not fertilized?
It will thicken and shed during menstruation
How long is the menstrual cycle?
28-29 days lasting for up to 2-7 days
What is the purpose of IUD
To prevent pregnancy.
Sex is determined by what at fertilization?
Determined by sex chromosomes in SPERM
What are the two sex chromosomes
X and Y
What is the female and male sex chromosome?
X = female
Y = male
How is pregnancy divided?
In three trimesters
How long does the fetus stage last for?
From 9th week until birth
What are some lifestyle choices that can affect a developing fetus?
Smoking, drinking, drugs
What is in-vitro fertilization?
When an egg and sperm cell are placed in a dish to become an embryo, later transfered into a uterus.
Why would someone partake in in-vitro fertilization?
When people who want children struggle to get pregnant.
