Question

key concept builder lesson 1
mendel and his peas
key concept why did mendel perform cross - pollination experiments?
directions: on each line, write the term from the word bank that correctly completes each sentence. each term is used only once.
color cross - breeding cross - pollination first
hybrid length reproduce second
self - pollination traits true - breeding

1. gregor mendel experimented with pea plants because they ______ quickly and have easily observed ______, and because he could control which plants reproduced.
2. pollination in pea plants can occur in the following two ways:

______ or ______.

1. mendel started with ________ plants—plants with the exact same characteristics from one generation to the next.
2. those characteristics included the ______ of the flowers and the ______ of the stems.
3. by ______ different pea plants, mendel produced a variety of ______ plants.
4. he noted that characteristics that were not present in a ______ - generation cross showed up in about 25 percent of the plants in a ______ - generation cross.

18 genetics

Explanation:

1. Pea plants reproduce quickly and have easily observed traits. Traits are the characteristics of an organism.
2. Pollination in pea plants can occur through self - pollination (pollen from the same plant fertilizes the ovule) or cross - pollination (pollen from one plant fertilizes the ovule of another plant).
3. True - breeding plants have the exact same characteristics from one generation to the next.
4. Flower color (e.g., purple or white) and stem length (e.g., tall or short) are common traits in pea plants.
5. By cross - breeding (which involves cross - pollination) different pea plants, hybrid plants (offspring of two different true - breeding varieties) are produced.
6. In Mendel's experiments, characteristics not present in the first - generation cross (e.g., recessive traits) showed up in about 25 percent of the second - generation cross.

Answer:

1. reproduce; traits
2. self - pollination; cross - pollination
3. true - breeding
4. color; length
5. cross - breeding; hybrid
6. first; second