science 1st semester final Flashcards
How are plant and animal cells different from one another?
Plant cells have cell walls, chloroplasts with chlorophyll, and a huge water-filled vacuole. Animals do not have any of these parts.
Why is the nucleus important to the cell?
It contains the genetic code and controls the cellular activities.
If you are looking at a single cell that is green in color, how would you know it is a plant cell?
Plants have chloroplasts filled with chlorophyll to trap energy from sunlight for photosynthesis.
What organelle surrounds an animal cell? Why is it so important that it functions properly?
cell membrane - regulates what can enter and leave the cell
What is the basic difference between autotrophs and heterotrophs?
autotrophs are producers - make food by photosynthesis heterotrophs are consumers - eat other organisms
Explain how photosynthesis and respiration are opposite processes of each other.
photosynthesis water + carbon dioxide yields sugar (food) + oxygen respiration sugar (food) + oxygen yields water + carbon dioxide The products of one are the reactants of the other.
How would raising the temperature of a liquid speed up diffusion?
Diffusion is movement using kinetic energy alone, and increasing temperature speeds particles up so they move faster.
Why is it not likely for eye color to be controlled by a single gene?
There are too many possible eye colors.
What are the genotypes of males and females? How are the alleles given to each of the offspring?
male - XY female - XX Females can only pass on an X. Males can pass on either an X or a Y.
How do codominant genes work?
They are both equally dominant, and both show up equally.
Contrast the effects of harmful and helpful mutations.
Harmful - make it less likely for survival Helpful - make it more likely for survival
What are three basic human needs?
food, water, shelter
What is a microscope?
a tool that magnifies objects to make small objects look larger
What are the two basic types of microscopes, and how are they different from each other?
compound light microscope - uses light to see living things - sees natural colors electron microscope - uses electrons to magnify even better, but object must be dead - sees black and white or computer colorized
Why is water necessary for life?
Most chemical reactions that take place in a cell need water to occur.
What is the name of life science?
biology
What is inferring?
using past or previous knowledge to predict something
What is homeostasis
maintaining a stable internal environment
What is the name of the variable that is purposely changed in a test or scientific experiment?
independent variable (IV
Define DNA replication and its function.
when DNA makes an exact copy of itself so that the new copy can control a new cell
What are the DNA nitrogen bases?
adenine - thymine - guanine - cytosine
What are the RNA nitrogen bases?
adenine - uracil - guanine - cytosine
What is the function of the cell membrane?
controls what goes in and out of the cell
Identify the shape of DNA.
double helix or spiral staircase
What are the characteristics all living things share?
- made of cells 2. contain hereditary material (DNA) 3. grow and develop 4. adapt and evolve 5. have a metabolism 6. react to stimuli 7. maintain homeostasis
What allele combination is a female?
XX
What allele combination is a male?
XY
the mistaken idea that living things could come from nonliving things
spontaneous generation
an action or change in behavior in reaction to a stimulus
response
a change in an organism’s surrounding environment that triggers a response
stimulus
the process by which plants and some microorganisms use water and carbon dioxide in the presence of sunlight to make their own food
photosynthesis
a segment of DNA on a chromosome that codes for a particular protein or trait
gene
an organism’s physical appearance
phenotype
a mistake or change in a gene or chromosome
mutation
having two identical alleles for a trait, TT or tt
homozygous
having two different alleles for a trait, Tt
heterozygous
a condition in which neither allele of a pair is dominant or recessive but they are equally expressed
codominant
a change in a gene or chromosome
mutation
an observation that deals with numbers or amounts
quantitative
an observation without numbers, an opinion
qualitative
What is the difference between organic and inorganic?
organic - contain carbon and are made by living things while inorganic - don’t contain carbon and are not made by living things
What is the difference between a hybrid and a purebred?
hybrid - 2 different things combines purebreds - 2 of the same things make babies
What is the difference between a genotype and a phenotype?
genotype is genetic makeup phenotype is a physical appearance
What is the percentage of recessive offspring in this Punnett square?
50% recessive 50% dominant
What is the percentage of dominant and recessive offspring in the Punnett square?
75% dominant
25% recessive
What is the form a hypothesis is usually written in?
if/then
What is the factor being tested in an experiment?
independent variable
What is being measured in a controlled experiment?
dependent variable
What are the factors that need to be kept the same between the experiment and the control?
constants
Which variable goes on which axis?
dry mix
What is the result of your experiment?
conclusion
